<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>01-first-line</title>
    <style>
        div {
            width: 200px;
            background-color: #f00;
        }
        
        /*div::first-line {
            color: green;
        }*/

        div::first-letter {
            color: green;
            font-size: 30px;
        }
    </style>
</head>
<body>

<div>这是文字我是文字我是文字我是文字我是文字我是文字我是文字我是文字我是文字</div>

</body>
</html>